Multilayered capacitor and board having the same mounted thereon

ABSTRACT

A multilayer capacitor includes: a capacitor body including first and second internal electrodes alternately stacked with a dielectric layer interposed therebetween, and having first to six surfaces, the first internal electrode being exposed through the third, fifth, and sixth surfaces, the second internal electrode being exposed through the fourth, fifth, and sixth surfaces; first and second side portions disposed on the fifth and sixth surfaces of the capacitor body; and first and second external electrodes. The capacitor body includes upper and lower cover portions disposed on an upper surface of an uppermost internal electrode and a lower surfaces of a lowermost internal electrode, respectively, in a stacking direction of the first and second internal electrodes. The first and second side portions and the upper and lower cover portions include zirconium (Zr).

CROSS-REFERENCE TO RELATED APPLICATION(S)

The present application claims the benefit of priority to Korean PatentApplication No. 10-2019-0084958, filed on Jul. 15, 2019 in the KoreanIntellectual Property Office, the entire disclosure of which isincorporated herein by reference.

TECHNICAL FIELD

The present disclosure relates to a multilayer capacitor and a mountingsubstrate thereof.

BACKGROUND

Electronic components using ceramic materials include capacitors,inductors, piezoelectric elements, varistors, or thermistors.

Among them, multilayer capacitors could be used in various electronicdevices due to their small size and high capacity.

Recently, the application range of multilayer capacitors has beenexpanded from IT products to electronic products. In particular,multilayer capacitors used in electronic products require highreliability due to harsh driving environments.

Such a multilayer capacitor includes a capacitor body formed of aceramic material, an internal electrode disposed inside the capacitorbody, and an external electrode installed on a surface of the capacitorbody to be connected to the internal electrode.

Recently, due to miniaturization and multifunctionality of electronicdevices, multilayer capacitors have also been required to be provided asa product with a small size and large capacity. To this end, an internalelectrode is allowed to be exposed in a width direction of a capacitorbody, so a multilayer capacitor having a structure in which an area in awidth direction of an internal electrode is significantly increased hasbeen manufactured.

In a multilayer capacitor having such a structure, a capacitor body ismanufactured, and then side portions are separately attached to bothsides in a width direction of the capacitor body in an operation beforesintering. Thus, the side portions cover exposed portions of theinternal electrode.

Further, multilayer capacitors having a structure in which an internalelectrode is exposed in a width direction of a capacitor body alsorequire a research to secure high reliability in order to meet standardsfor electronic devices and electric apparatuses.

SUMMARY

An aspect of the present disclosure is to provide a multilayer capacitorin which a side portion and a cover region of a capacitor body includeZr to improve reliability, and a mounting surface thereof.

According to an aspect of the present disclosure, a multilayer capacitorincludes: a capacitor body including first and second internalelectrodes alternately stacked with a dielectric layer interposedtherebetween, and having first and second surfaces opposing each other,third and fourth surfaces connected to the first and second surfaces andopposing each other, and fifth and sixth surfaces connected to the firstand second surfaces, connected to the third and fourth surfaces, andopposing each other. The first internal electrode is exposed through thethird, fifth, and sixth surfaces, and the second internal electrode isexposed through the fourth, fifth, and sixth surfaces; first and secondside portions disposed on the fifth and sixth surfaces of the capacitorbody, respectively. The multilayer capacitor further includes first andsecond external electrodes disposed on the third and fourth surfaces ofthe capacitor body, respectively, and connected to the first and secondinternal electrodes, respectively. The capacitor body includes upper andlower cover portions disposed on an upper surface of an uppermostinternal electrode and a lower surfaces of a lowermost internalelectrode, respectively, in a stacking direction of the first and secondinternal electrodes. The first and second side portions and the upperand lower cover portions include zirconium (Zr).

Each of the first and second side portions and the upper and lower coverportions may include the Zr content equal to or less than 1 mol %.

The first and second side portions may further include magnesium (Mg).

Each of the first and second side portions may include the Mg content of10 mol % to 30 mol %, in comparison to BaTiO₃ (BT).

The upper and lower cover portions may further include magnesium (Mg).

Each of the upper and lower cover portions may include the Mg content of10 mol % to 30 mol %, in comparison to BT.

An average thickness of the first and second internal electrodes may beequal to or less than 0.41 μm.

An average thickness of the dielectric layer may be equal to or lessthan 0.4 μm.

The multilayer capacitor may have a length of 1.0 mm, and a width of 0.5mm.

The first and second external electrodes may respectively include: firstand second connecting portions disposed on the third surface and thefourth surface of the capacitor body, respectively, and connected to thefirst and second internal electrodes; and first and second band portionsextended to a portion of the first surface of the capacitor body fromthe first and second connecting portions.

According to another aspect of the present disclosure, a mountingsubstrate of a multilayer capacitor includes: a substrate having firstand second electrode pads on one surface; and a multilayer capacitormounted to allow first and second external electrodes to be connected tothe first and second electrode pads, respectively.

Other features and aspects will be apparent from the following detaileddescription, the drawings, and the claims.

BRIEF DESCRIPTION OF DRAWINGS

The above and other aspects, features, and advantages of the presentdisclosure will be more clearly understood from the following detaileddescription taken in conjunction with the accompanying drawings, inwhich:

FIG. 1 is a schematic perspective view of a multilayer capacitoraccording to an exemplary embodiment of the present disclosure;

FIG. 2 is a cross-sectional view taken along line I-I′ of FIG. 1;

FIGS. 3A and 3B are cross-sectional views illustrating a structure ofeach of first and second internal electrodes, respectively, applied tothe multilayer capacitor of FIG. 1;

FIG. 4 is a cross-sectional view taken along line II-II′ of FIG. 1;

FIG. 5 is a cross-sectional view taken along line III-III′ of FIG. 1;

FIGS. 6, 7, and 8 are SEM images in which grains of side portionsaccording to Comparative Example, Example 1, and Example 2 are enlarged;

FIG. 9 is a schematic cross-sectional view illustrating the multilayercapacitor of FIG. 2 mounted on a substrate; and

FIG. 10 is a graph illustrating Insulation Resistance (IR) according tothe Zr content of a side portion and a cover portion.

DETAILED DESCRIPTION

Hereinafter, embodiments of the present disclosure will be described asfollows with reference to the attached drawings.

The present disclosure may, however, be exemplified in many differentforms and should not be construed as being limited to the specificembodiments set forth herein. Rather, these embodiments are provided sothat this disclosure will be thorough and complete, and will fullyconvey the scope of the disclosure to those skilled in the art.

Throughout the specification, it will be understood that when anelement, such as a layer, region or wafer (substrate), is referred to asbeing “on,” “connected to,” or “coupled to” another element, it can bedirectly “on,” “connected to,” or “coupled to” the other element orother elements intervening therebetween may be present. In contrast,when an element is referred to as being “directly on,” “directlyconnected to,” or “directly coupled to” another element, there may be noelements or layers intervening therebetween. Like numerals refer to likeelements throughout. As used herein, the term “and/or” includes any andall combinations of one or more of the associated listed items.

It will be apparent that though the terms first, second, third, etc. maybe used herein to describe various members, components, regions, layersand/or sections, these members, components, regions, layers and/orsections should not be limited by these terms. These terms are only usedto distinguish one member, component, region, layer or section fromanother region, layer or section. Thus, a first member, component,region, layer or section discussed below could be termed a secondmember, component, region, layer or section without departing from theteachings of the exemplary embodiments.

Spatially relative terms, such as “above,” “upper,” “below,” and “lower”and the like, may be used herein for ease of description to describe oneelement's relationship to another element(s) as shown in the figures. Itwill be understood that the spatially relative terms are intended toencompass different orientations of the device in use or operation inaddition to the orientation depicted in the figures. For example, if thedevice in the figures is turned over, elements described as “above,” or“upper” other elements would then be oriented “below,” or “lower” theother elements or features. Thus, the term “above” can encompass boththe above and below orientations depending on a particular direction ofthe figures. The device may be otherwise oriented (rotated 90 degrees orat other orientations) and the spatially relative descriptors usedherein may be interpreted accordingly.

The terminology used herein describes particular embodiments only, andthe present disclosure is not limited thereby. As used herein, thesingular forms “a,” “an,” and “the” are intended to include the pluralforms as well, unless the context clearly indicates otherwise. It willbe further understood that the terms “comprises,” and/or “comprising”when used in this specification, specify the presence of statedfeatures, integers, steps, operations, members, elements, and/or groupsthereof, but do not preclude the presence or addition of one or moreother features, integers, steps, operations, members, elements, and/orgroups thereof.

Hereinafter, embodiments of the present disclosure will be describedwith reference to schematic views illustrating embodiments of thepresent disclosure. In the drawings, for example, due to manufacturingtechniques and/or tolerances, modifications of the shape shown may beestimated. Thus, embodiments of the present disclosure should not beconstrued as being limited to the particular shapes of regions shownherein, for example, to include a change in shape results inmanufacturing. The following embodiments may also be constituted by oneor a combination thereof.

The contents of the present disclosure described below may have avariety of configurations and propose only a required configurationherein, but are not limited thereto.

When orientations are defined to clearly describe an exemplaryembodiment of the present disclosure, X, Y, and Z on the drawingsindicate a length direction, a width direction, and a thicknessdirection of a multilayer capacitor, respectively.

Moreover, in an exemplary embodiment of the present disclosure, a Zdirection may be used as having the same meaning as a stacking directionin which dielectric layers are stacked on each other.

FIG. 1 is a schematic perspective view of a multilayer capacitoraccording to an exemplary embodiment of the present disclosure, FIG. 2is a cross-sectional view taken along line I-I′ of FIG. 1, FIGS. 3A and3B are cross-sectional views illustrating a structure of each of firstand second internal electrodes, respectively, applied to the multilayercapacitor of FIG. 1, FIG. 4 is a cross-sectional view taken along lineII-II′ of FIG. 1, and FIG. 5 is a cross-sectional view taken along lineIII-III′ of FIG. 1.

Next, a multilayer capacitor according to an exemplary embodiment of thepresent disclosure will be described with reference to FIGS. 1 to 5.

Referring to FIGS. 1 to 5, a multilayer capacitor 100 according to anexemplary embodiment of the present disclosure includes a capacitor body110, first and second side portions 141 and 142, and first and secondexternal electrodes 131 and 132.

In this case, the first and second side portions 141 and 142 includezirconium (Zr).

In addition, the capacitor body 110 includes an active area 115 andupper and lower cover portions 112 and 113.

In this case, the upper and lower cover portions 112 and 113 include Zr.

In an exemplary embodiment of the present disclosure, the active areadoes not include Zr, while a margin portion, upper and lower coverportions and a side portion include Zr. Thus, density of a side portionand a cover portion is increased and a breakdown voltage (BDV) isincreased, and reliability is improved.

Moreover, a length of the multilayer capacitor 100 in an X direction,according to an exemplary embodiment of the present disclosure, is 1.0mm, and a width thereof in a Y direction is 0.5 mm.

The plurality of dielectric layers 111, forming the capacitor body 110,are stacked in the Z direction and then sintered, and adjacentdielectric layers 111 of the capacitor body 110 are integrated so thatboundaries therebetween are not readily apparent without using ascanning electron microscope (SEM).

In addition, the capacitor body 110 includes a plurality of dielectriclayers 111 and first and second internal electrodes 121 and 122 havedifferent polarities and alternately arranged in the Z direction withthe dielectric layer 111 interposed therebetween.

Moreover, the capacitor body 110 may include an active area as a portionwhich contributes to the formation of the capacity of a capacitor, andupper and lower cover portions 112 and 113 as a margin portion. In theactive area, the first and second internal electrodes are alternatelydisposed in the Z direction with the dielectric layer 111 interposedtherebetween. The upper and lower cover portions are provided on upperand lower surfaces of the active area in the Z direction, respectively.

The capacitor body 110, described above, has a shape without limitation,and may have a hexahedral shape, and may include a first surface 1 and asecond surface 2, opposing each other in the Z direction, a thirdsurface 3 and a fourth surface 4, connected to the first surface 1 andthe second surface 2 and opposing each other in the X direction, and afifth surface 5 and a sixth surface 6, connected to the first surface 1and the second surface 2, connected to the third surface 3 and thefourth surface 4 and opposing each other. In this case, the firstsurface 1 may be a mounting surface.

The dielectric layer 111 may include ceramic powder, for example,BaTiO₃-based ceramic powder, or the like.

Moreover, the BaTiO₃-based ceramic powder may be (Ba_(1−x)Ca_(x))TiO₃,Ba(Ti_(1−y)Ca_(y)) O₃, (Ba_(1−x)Ca_(x))(Ti_(1−y)Zr_(y)) O₃,Ba(Ti_(1−y)Zr_(y))O₃, or the like, in which Ca or Zr is partiallydissolved in BaTiO₃(BT), but an embodiment of the present disclosure isnot limited thereto.

Moreover, a ceramic additive, an organic solvent, a plasticizer, abinder, a dispersant, and the like may also be added to the dielectriclayers 111 along with the ceramic powder.

The ceramic additive may include, for example, a transition metal oxideor a transition metal carbide, a rare earth element, magnesium (Mg),aluminum (Al), or the like.

The first and second internal electrodes 121 and 122 are electrodes towhich different polarities are applied, are formed on the dielectriclayer 111 and stacked on the Z direction, and may be arrangedalternately to oppose each other in the Z direction inside the capacitorbody 110 with a single dielectric layer 111 interposed therebetween.

In this case, the first and second internal electrodes 121 and 122 maybe electrically isolated from each other by the dielectric layers 111interposed therebetween.

Moreover, the first internal electrode 121 is exposed through the thirdsurface 3, the fifth surface 5, and the sixth surface 6, of thedielectric layer 111. In this case, the first internal electrode 121 mayalso be exposed through a corner connecting the third surface 3 to thefifth surface 5 of the capacitor body 110 and a corner connecting thethird surface 3 to the sixth surface 6 of the capacitor body 110.

The second internal electrode 122 is exposed through the fourth surface4, the fifth surface 5, and the sixth surface 6, of the dielectric layer111. In this case, the second internal electrode 122 may also be exposedthrough a corner connecting the fourth surface 4 to the fifth surface 5of the capacitor body 110 and a corner connecting the fourth surface 4to the sixth surface 6 of the capacitor body 110.

In this case, end portions of the first and second internal electrodes121 and 122, alternately exposed through the third surface 3 and thefourth surface 4 of the capacitor body 110, may be in contact with andelectrically connected to the first and second external electrodes 131and 132, disposed on both end portions of the capacitor body 110 in theX direction, to be described later.

According to the above configuration, when a predetermined voltage isapplied to the first and second external electrodes 131 and 132, chargesare accumulated between the first and second internal electrodes 121 and122.

In this case, the capacitance of the multilayer capacitor 100 isproportional to an area of overlap between the first and second internalelectrodes 121 and 122, overlapping each other in the Z direction in theactive area 115.

As in an exemplary embodiment of the present disclosure, when the firstand second internal electrodes 121 and 122 are configured, not onlybasic areas of the first and second internal electrodes 121 and 122 areexpanded, but also the capacity of the multilayer capacitor 100 may beincreased by increasing an area vertically overlapped.

Moreover, a stepped portion caused by an internal electrode may bereduced, so the accelerated life of insulation resistance may beimproved. Thus, a multilayer capacitor with excellent capacitycharacteristics and improved reliability may be provided.

In this case, a material, forming the first and second internalelectrodes 121 and 122, is not particularly limited. For example, thefirst and second internal electrodes may be formed using a preciousmetal material or a conductive paste formed of at least one betweennickel (Ni) and copper (Cu).

In addition, a method of printing the conductive paste such as screenprinting or gravure printing may be used, but an embodiment of thepresent disclosure is not limited thereto.

The first side portion 141 is disposed on the fifth surface 5 of thecapacitor body 110, while the second side portion 142 is disposed on thesixth surface 6 of the capacitor body 110.

The first and second side portions 141 and 142 are in contact with frontends to cover the front ends of portions exposed through the fifthsurface 5 and the sixth surface 6 of the capacitor body 110 in the firstand second internal electrodes 121 and 122.

The first and second side portions 141 and 142 may serve to protect thecapacitor body 110 and the first and second internal electrodes 121 and122 from an external impact, and to secure insulation properties andmoisture resistance reliability around the capacitor body 110.

Voltages having different polarities are provided for the first andsecond external electrodes 131 and 132, and the first and secondexternal electrodes are disposed in both end portions of the capacitorbody 110 in the X direction and are in contact with and electricallyconnected to portions exposed through the third surface 3 and the fourthsurface 4 of the capacitor body 110 in the first and second internalelectrodes 121 and 122.

The first external electrode 131 may include a first connection portion131 a and a first band portion 131 b.

The first connecting portion 131 a is disposed on the third surface 3 ofthe capacitor body 110, and in contact with an end portion exposedexternally through the third surface 3 of the capacitor body 110 in thefirst internal electrode 121 to physically and electrically connect thefirst internal electrode 121 to the first external electrode 131.

The first band portion 131 b is a portion extended from the firstconnecting portion 131 a to a portion of the first surface 1 of thecapacitor body 110.

In this case, the first band portion 131 b is further extended to thesecond surface 2, the fifth surface 5, and the sixth surface 6 of thecapacitor body 110 to improve adhesion strength if required, so as tocover one end portion of the first and second side portions 141 and 142.

The second external electrode 132 may include a second connectionportion 132 a and a second band portion 132 b.

The second connecting portion 132 a is disposed on the fourth surface 4of the capacitor body 110, and in contact with an end portion exposedexternally through the second surface 4 of the capacitor body 110 in thesecond internal electrode 122 to physically and electrically connect thesecond internal electrode 122 to the second external electrode 132.

The second band portion 132 b is a portion extended from the secondconnecting portion 132 a to a portion of the first surface 1 of thecapacitor body 110.

In this case, the second band portion 132 b is further extended to thesecond surface 2, the fifth surface 5, and the sixth surface 6 of thecapacitor body 110 to improve adhesion strength if required, so as tocover the other end portion of the first and second side portions 141and 142.

In general, in a process of forming a side portion, a large amount ofvoids are generated at an interface in which a capacitor body and a sideportion are in contact with each other, so reliability may be degraded.

Moreover, due to a void generated at an interface in which a capacitorbody and a side portion are in contact with each other, a concentrationof an electric field is generated. Thus, a breakdown voltage (BDV) maybe lowered.

In addition, due to the void, outer sintering density is lowered, sodegradation of moisture resistance reliability may be caused.

According to an exemplary embodiment of the present disclosure, Zr isadded to a side portion and a cover portion. Thus, an oxide layer may beformed in a void generated at an interface in which an active area of acapacitor body and the side portion and the cover portion are in contactwith each other.

As described above, when an oxide layer is formed in a void generated aninterface in which a capacitor body and a side portion are in contactwith each other, insulating properties are obtained to mitigate aconcentration of an electric field. Accordingly, a breakdown voltage(BDV) is increased and a short defect may be reduced.

In an exemplary embodiment of the present disclosure, the first andsecond side portions 141 and 142 and the upper and lower cover portions112 and 113 may include the Zr content equal to or less than 1 mol % ascompared with a total mol of the first and second side portions 141 and142 and the upper and lower cover portions 112 and 113.

FIG. 10 is a graph illustrating Insulation Resistance (IR) according tothe Zr content of a side portion and a cover portion.

In FIG. 10, #1 is the case in which Zr is not included in first andsecond side portions, in addition to upper and lower cover portions, #2is the case in which Zr in an amount of 0.5 mol % is included in thefirst and second side portions, in addition to the upper and lower coverportions, and #3 is the case in which Zr in an amount of 1.0 mol % isincluded in the first and second side portions, in addition to the upperand lower cover portions.

In FIG. 10, when Zr is included, it is confirmed that dispersion ofmoisture resistance reliability is improved. In detail, it is confirmedthat, as the Zr content is increased, the dispersion of moistureresistance reliability is further improved.

Moreover, in the first and second side portions 141 and 142, in additionto the upper and lower cover portions 112 and 113, if the Zr contentexceeds 1 mol % as compared with the total mol, sintering of BT issignificantly reduced. Thus, it may be difficult to implementcapacitance characteristics of a multilayer capacitor at the sametemperature level.

In addition, during sintering, sintering of a dielectric layer and aninternal electrode is mismatched, so electrical characteristics of amultilayer capacitor may be degraded, and strength and reliability maybe lowered.

Moreover, the first and second side portions 141 and 142 may furtherinclude magnesium (Mg).

As described above, when the first and second side portions 141 and 142further include magnesium, an oxide layer may be formed in a voidgenerated at an interface in which an active area of a capacitor bodyand the side portion and the cover portion are in contact with eachother.

In this case, the first and second side portions 141 and 142 may includethe Mg content of 10 mol % to 30 mol % in comparison to BT.

When the first and second side portions 141 and 142 include Mg, an oxidelayer may be formed in a void formed at an interface in which a sideportion and a capacitor body are in contact with each other.

When the Mg content is increased in the first and second side portions141 and 142, a length of an oxide layer is increased. Thus, the oxidelayer blocks a void to form an insulating layer.

Moreover, the insulating layer prevents a concentration of an electricfield to improve BDV of a multilayer capacitor, and reliability of themultilayer capacitor may be improved due to a reduction in the void.

In each of the first and second side portions 141 and 142, when the Mgcontent is equal to or more than 10 mol % in comparison to BT, theeffect described above may be properly obtained.

Moreover, in each of the first and second side portions 141 and 142, ifthe Mg content exceeds 30 mol % in comparison to BT, sintering isdegraded. Thus, a pore in the first and second side portions 141 and 142is significantly increased, and dispersion of BDV is poor, soreliability of a multilayer capacitor may be degraded.

In addition, the upper and lower cover portions 112, 113 may furtherinclude magnesium (Mg).

In this case, each of the upper and lower cover portions 112 and 113 mayinclude the Mg content of 10 mol % to 30 mol %, in comparison to BT.

When Mg is included in the upper and lower cover portions 112 and 113,an oxide layer may be formed in a void formed at an interface in whichthe upper and lower cover portions 112 and 113 and the active area ofthe capacitor body are in contact with each other.

When the Mg content is increased in the upper and lower cover portions112 and 113, a length of an oxide layer is increased, so the oxide layerblocks a void to form an insulating layer.

Moreover, the insulating layer prevents a concentration of an electricfield to improve BDV of a multilayer capacitor, and reliability of themultilayer capacitor may be improved due to a reduction in the void.

In each of the upper and lower cover portions 112 and 113, only when theMg content is equal to or more than 10 mol % in comparison to BT, maythe effect described above be properly obtained.

Moreover, in each of the upper and lower cover portions 112 and 113, ifthe Mg content exceeds 30 mol % in comparison to BT, sintering isdegraded. Thus, a pore in the upper and lower cover portions 112 and 113is significantly increased, and dispersion of BDV is poor, soreliability of a multilayer capacitor may be degraded.

FIGS. 6, 7, and 8 are SEM images in which grains of side portionsaccording to Comparative Example, Example 1, and Example 2, are enlarged

Here, Comparative Example is the case in which a side portion does notinclude Zr, Example 1 is the case in which a side portion includes Zr of0.5 mol % as comparison with the total mol, and Example 2 is the case inwhich a side portion includes Zr 1.0 mol % in comparison with the totalmol.

Referring to FIGS. 6 to 8, in the case of Examples 1 and 2 in which Zris included, compared to Comparative Example, it is confirmed that,while growth of grain size is suppressed, sintering density isincreased.

In detail, in the case of Example 2 in which the Zr content of 1.0 mol %is included in comparison with the total mol of a side portion, comparedto Example 1, it is confirmed that, while growth of grain size isfurther suppressed, sintering density is further increased.

Thus, in the case of Example 1 and Example 2 of the present disclosure,compared to Comparative Example, reliability may be further improved. InExample 2, compared to Example 1, reliability may be further improved.

In addition, although not illustrated, even in upper and lower coverportions, according to whether Zr is included and the Zr content, atendency similar to a side portion may be provided.

Furthermore, in an exemplary embodiment of the present disclosure, anaverage thickness of a dielectric layer 111 may be equal to or less than0.4 μm.

In addition, an average thickness of the first and second internalelectrodes 121 and 122 may be equal to or less than 0.41 μm.

The multilayer capacitor according to an exemplary embodiment of thepresent disclosure has a structure in which first and second internalelectrodes 121 and 122 are exposed through the fifth and sixth surfacesof the capacitor body, so a step of an end portion of an internalelectrode in a width direction may be improved.

In this regard, even when thicknesses of the dielectric layer and thefirst and second internal electrodes are reduced as described above anda multilayer is thin, a significant problem does not occur in terms ofreliability. Thus, while reliability of a multilayer capacitor issecured, capacity may also be increased.

In addition, when an average thickness of an internal electrode isreduced, a shrinkage rate after sintering is reduced. Thus, a diameterof an end of a capacitor body becomes smaller, and it is advantageous toimprove reliability of a multilayer capacitor.

Thus, when an average thickness of a dielectric layer is equal to orless than 0.4 μm, and an average thickness of the first and secondinternal electrodes 121 and 122 is equal to or less than 0.41 μm, adiameter of a void is reduced. Thus, an oxide layer may be easily formedat an interface of a capacitor body and a side portion and an interfaceof an active area and a cover portion.

Referring to FIG. 9, a mounting substrate of a multilayer capacitoraccording to an exemplary embodiment of the present disclosure includesa substrate 210 having first and second electrode pads 221 and 222 onone surface, in addition to a multilayer capacitor 100 mounted toconnect first and second external electrodes 131 and 141 to the firstand second electrode pads 221 and 222, respectively, on an upper surfaceof the substrate 210.

In an exemplary embodiment of the present disclosure, although themultilayer capacitor 100 is illustrated and described as being mountedon the substrate 210 by solders 231 and 232, a conductive paste may beused instead of solder if necessary.

As set forth above, according to an exemplary embodiment of the presentdisclosure, an internal electrode is exposed to both sides in a widthdirection of a capacitor body, and then a side portion is attachedseparately. Thus, an overlapping area between internal electrodes issignificantly increased, so capacity of a multilayer capacitor may beincreased. Moreover, as a side portion and a cover portion include Zr,density of the side portion and the cover portion is improved, soreliability of a multilayer capacitor may be increased.

While exemplary embodiments have been shown and described above, it willbe apparent to those skilled in the art that modifications andvariations could be made without departing from the scope of the presentinvention as defined by the appended claims.

What is claimed is:
 1. A multilayer capacitor, comprising: an activearea, which contributes to formation of capacity of the multilayercapacitor, including first and second internal electrodes alternatelystacked with a dielectric layer interposed therebetween, the active areahaving third and fourth surfaces opposing each other, and fifth andsixth surfaces connected to the third and fourth surfaces and opposingeach other, the first internal electrode being in contact with thethird, fifth, and sixth surfaces, the second internal electrode being incontact with the fourth, fifth, and sixth surfaces; first and secondside portions disposed on the fifth and sixth surfaces of the activearea, respectively, to contact the first and second internal electrodes;and first and second external electrodes disposed on the third andfourth surfaces of the active area, respectively, and connected to thefirst and second internal electrodes, respectively, wherein among aportion of the dielectric layer in the active region and one of thefirst and second side portions, only the one of the first and secondside portions includes zirconium (Zr).
 2. The multilayer capacitor ofclaim 1, wherein a Zr content of the one of the first and second sideportions is equal to or less than 1 mol%.
 3. The multilayer capacitor ofclaim 1, wherein the one of the first and second side portions furtherincludes magnesium (Mg).
 4. The multilayer capacitor of claim 3, whereinthe one of the first and second side portions includes an Mg content of10 mol% to 30 mol% in comparison to BaTiO₃ (BT).
 5. The multilayercapacitor of claim 1, wherein an average thickness of the first andsecond internal electrodes is equal to or less than 0.41 μm.
 6. Themultilayer capacitor of claim 1, wherein an average thickness of thedielectric layer is equal to or less than 0.4 μm.
 7. The multilayercapacitor of claim 1, wherein the multilayer capacitor has a length of1.0 mm, and a width of 0.5 mm.
 8. The multilayer capacitor of claim 1,further comprising upper and lower cover portions disposed on an uppersurface of an uppermost internal electrode and a lower surface of alowermost internal electrode, respectively, in a stacking direction ofthe first and second internal electrodes, and wherein one of the upperand lower cover portions includes zirconium (Zr).
 9. The multilayercapacitor of claim 8, wherein a Zr content of the one of the upper andlower cover portions is equal to or less than 1 mol%.
 10. The multilayercapacitor of claim 8, wherein the one of the upper and lower coverportions further includes magnesium (Mg).
 11. The multilayer capacitorof claim 10, wherein the one of the upper and lower cover portionsincludes an Mg content of 10 mol% to 30 mol% in comparison to BaTiO₃(BT).
 12. A multilayer capacitor, comprising: an active area, whichcontributes to formation of capacity of the multilayer capacitor,including first and second internal electrodes alternately stacked witha dielectric layer interposed therebetween, the active area having thirdand fourth surfaces opposing each other, and fifth and sixth surfacesconnected to the third and fourth surfaces and opposing each other, thefirst internal electrode being in contact with the third, fifth, andsixth surfaces, the second internal electrode being in contact with thefourth, fifth, and sixth surfaces; first and second side portionsdisposed on the fifth and sixth surfaces of the active area,respectively, to contact the first and second internal electrodes; upperand lower cover portions disposed on an upper surface of an uppermostinternal electrode and a lower surface of a lowermost internalelectrode, respectively, in a stacking direction of the first and secondinternal electrodes; and first and second external electrodes disposedon the third and fourth surfaces of the active area, respectively, andconnected to the first and second internal electrodes, respectively,wherein among a portion of the dielectric layer in the active region andone of the upper and lower cover portions, only the one of the upper andlower cover portions includes zirconium (Zr).
 13. The multilayercapacitor of claim 12, wherein an average thickness of the first andsecond internal electrodes is equal to or less than 0.41 μm.
 14. Themultilayer capacitor of claim 12, wherein an average thickness of thedielectric layer is equal to or less than 0.4 μm.
 15. The multilayercapacitor of claim 12, wherein the multilayer capacitor has a length of1.0 mm, and a width of 0.5 mm.
 16. The multilayer capacitor of claim 12,wherein a Zr content of the one of the upper and lower cover portions isequal to or less than 1 mol%.
 17. The multilayer capacitor of claim 12,wherein the one of the upper and lower cover portions further includesmagnesium (Mg).
 18. The multilayer capacitor of claim 17, wherein theone of the upper and lower cover portions includes an Mg content of 10mol% to 30 mol% in comparison to BaTiO₃ (BT).